Stimuli which evoke and/or control aggressive responses, and the social mechanisms invoked in agonistic encounters and in the maintenance of group cohesion will be studied in long term groups of primates using a series of temporary introductions. Two stimuli classes are differentiated, 1) those relating to more or less permanent properties of the individual and 2) those relating to the behavior of the individual, including communication responses and general patterns. Type one will be investigated using animals of different ages, both sexes, multiple species and differential prior familiarity. Type two will be investigated by anesthetization of subjects as well as extraspecifics, multiple individuals and instructed human intruders. Between introductions data will also be collected directed at explicating: the roles of ranking females, the influence of genealogy and matriarch survival, the influence of past peer play associations and hormonal states in their effects upon cohesive social relationships, mobbing responses and agonistic expressions. Later introductions will explore the agonistic buffering qualities of associative introductions. The effects of social reorganization upon aggressive responses and cohesion will also be explored.